1. Field of the Invention
The present invention relates to a substrate for display device, a liquid crystal display panel, a liquid crystal display device and an organic electroluminescent display device. More specifically, the present invention relates to a substrate for display device suitably used as a color filter substrate for color liquid crystal display device and the like, and a liquid crystal display panel, a liquid crystal display device and an organic electroluminescent device each comprising the substrate for display device.
2. Description of the Related Art
Recently, there is growing demand for a liquid crystal display, especially a color liquid crystal display with expansion of market of liquid crystal TV. For much more spread of this color liquid crystal display in future, reduction of production costs are needed. Especially, it is necessary to provide a cheaper color filter (CF) substrate.
With the above needs, an ink jet method has been studied for formation of a colored layer in a CF substrate. In formation of a CF substrate by an ink jet method, for example, a black matrix is firstly formed on a substrate, and then a colored layer is formed by applying an ink to a pixel region, which is an opening in the black matrix, using an ink jet printer. The formation process of the colored layer by such an ink jet method has an advantage of low costs because photolithography is not necessary to use.
However, a droplet on the substrate has a shape of part of sphere as shown in FIG. 6. Therefore, the droplet applied to the pixel region of the CF substrate has a thinner thickness in the periphery of the pixel region, especially in four corners (FIG. 7b) of the rectangular pixel region as shown in FIG. 7, although it has a sufficient thickness in the central part (FIG. 7c) of the pixel region. Accordingly, unevenness of color density within the pixel may occur, leading to reduction in display quality of display images. In FIG. 7b, the outline arrow expresses light leakage. On the other hand, when the amount of the droplet is increased and spread on the black matrix as shown in FIG. 8a in order to suppress the light leakage, it becomes easy to cause color mixture because ink droplets are mixed (leaked) with each other between adjacent pixels as shown in FIG. 8b. 
Japanese Kokai Publication Hei-08-220331 discloses an invention to form chamfered corner parts of a CF (colored layer) in etching process of the CF formed by application as an art to suppress embossment in the corner parts of the CF when the CF is prepared in the photo process. However, the invention disclosed in Japanese Kokai Publication Hei-08-220331 is not an art suitable for solving the above-mentioned problems in that an ink jet method is not assumed as a formation process of the colored layer; an art, in which a portion worsening display quality is removed from the colored layer, is used for improving display quality; and the invention has an object to prevent defect in a cell gap to uniform the cell cap.
Also, Japanese Kokai Publication Hei-08-106084 discloses an invention to provide a chamfered part in advance at an end of a corner of a photomask pattern for forming pattern as an art in order to prevent generation of protruding-shape resist residues in corner parts of the pattern at the time of forming a resin black matrix. However, the invention disclosed in Japanese Kokai Publication Hei-08-106084 is not an art suitable for solving the above-mentioned problems in that the invention has an object to prevent display unevenness caused by variation in size of the resist residues of protruding shape.
Furthermore, Japanese Kokai Publication Hei-08-271720, discloses a CF (CF substrate) having excel lent smoothness and less decolored portions, in which at least one of four angle parts of substantially rectangular apertures is substantially circular arc shape, and the adjacent apertures colored with different colors from each other are partitioned by a color mixture preventive wall. However, there is no description in Japanese Kokai Publication Hei-08-271720 about a configuration of the color mixture preventive wall suitable for solving the above-mentioned problems.